SANTA ROSA and PETALUMA — Ghilotti Construction Co. and North Bay Construction, two of the largest locally based general engineering contractors, today said they will combine operations over the next 18 months.

North Bay Construction founder and Chief Executive Officer John Barella, 62, inked a deal to sell the assets to Ghilotti Construction by the end of 2012. Mr. Barella is ending his management of the company, and North Bay President Steven Geney, 52, is joining Ghilotti Construction management team.